FXUS61 KRLX 240533
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1230 AM EST THU DEC 24 2009
.SYNOPSIS...
HIGH PRESSURE TONIGHT...SHIFTS EAST AS TEMPERATURES TURN WARMER
THURSDAY. RAINY AND WINDY OCCLUDED FRONT EXPECTED THURSDAY NIGHT
THROUGH CHRISTMAS. TURNING COLDER AGAIN THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...LOWERED THE MIN T TONIGHT IN THE NORTHEAST ZONES WITH DRY
AIR ADVECTING IN WITH LIGHT NORTHEAST SURFACE FLOW.
OTHERWISE...WILL SEE A SLOW INCREASE TO THE CLOUD COVER BY DAWN.
PREVIOUS DISCUSSION...HIGH PRESSURE RIDGE TO OUR NW WILL BREAK
DOWN DURING THE OVERNIGHT AND INTO THURSDAY. STORM SYSTEM OVER THE
LOWER MISSISSIPPI VALLEY WILL MOVE NORTHWARD DURING THE DAY
TOMORROW. MODELS CONTINUE TO SLOW SYSTEM DOWN A TAD AS LOW WINDS
UP. WAA ON SOUTHERLY FLOW WILL WARM TEMPERATURES TOMORROW INTO THE
30S AND 40S WITH CLOUDS INCREASING AS WELL. OCCLUDED FRONT
APPROACHES LATE IN THE DAY TOMORROW AND INTRODUCED SLGT CHC POPS
OVER EXTREME SOUTHERN ZONES. WENT WITH A BLEND OF GEM/GMOS/MET
GUIDANCE FOR LOWS AND HIGHS.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
STRONG LOW PRESSURE WILL LIFT WELL NORTH AND WEST OF OUR AREA
CHRISTMAS EVE AND CHRISTMAS DAY. WARM FRONT WILL LIFT NORTH
CHRISTMAS EVE NIGHT...FOLLOWED BY A COLD FRONT CHRISTMAS DAY. STRONG
SURFACE HIGH PRESSURE RIDGING SOUTHWARD EAST OF THE MOUNTAINS WILL
BE SLOW TO GET DISLODGED BY THE APPROACHING SYSTEM. MODELS CONTINUED
SHOWING A RELATIVE DRY SLOT FRIDAY NIGHT INTO SATURDAY BEHIND THE
COLD FRONT...BEFORE WRAPAROUND MOISTURE AND COLD ADVECTION COME BACK
IN FORCE DURING SATURDAY.
TEMPERATURES AT OR BELOW FREEZING...TRAPPED ACROSS THE EAST FACING
SLOPES OF THE EASTERN MOUNTAINS WILL PRODUCE LIQUID PCPN TO FREEZE
THRU NGT INTO FRI. CODED WIDESPREAD AREAS OF ICE ACROSS MOST OF
POCAHONTAS AND RANDOLPH COUNTIES WITH ACCUMULATIONS AROUND 0,.25
INCHES OF ICE. OTHER COUNTIES SOUTH TO RALEIGH COULD SEE HIGHER ICE
ACCUMULATIONS BUT CONFINED TO THEIR EASTERN SLOPES. A WINTER STORM
WATCH WAS ISSUED FOR FREEZING RAIN FOR POCA AND RANDOLPH COUNTIES.
TEMPERATURES WILL REALLY REBOUND AHEAD OF THE COLD FRONT
FRIDAY...WITH GUSTY SOUTH WINDS.
THE REST OF THE AREA WILL EXPERIENCE STRATIFORM RAIN...AS THE WARM
FRONT LIFTS OUT. AROUND A HALF INCH OF RAINFALL IS EXPECTED MOST
AREAS...WHICH SHOULD NOT BE ENOUGH TO CAUSE SIGNIFICANT FLOODING
WITH THE MELTING SNOW PACK. HOWEVER...IF MORE RAINFALL OCCURS...THEN
THIS WOULD BECOME MORE OF A PROBLEM. FOR NOW...NO MENTION OF
FLOODING ISSUES.
THE NAM AND GFS SHOW 60 TO 70 KNOTS FROM THE SOUTHEAST AT H850. SAME
STRONG WINDS ARE EVIDENT ON 290K ISENTROPIC SFC DOWNGLIDING TO THE
GROUND ACROSS THE MOUNTAINS THU NIGHT. THEREFORE...ISSUE A HIGH WIND
WATCH WHERE THE ISENTROPIC WINDS ARE THE HIGHEST FROM FAYETTE SOUTH
TO DICKENSON COUNTY. A WIND ADVISORY MAY BE REQUIRED FOR SOME OF THE
WESTERN SLOPES AND THE REST OF THE EASTERN MOUNTAINS NORTH TO
RANDOLPH THU NGT INTO FRIDAY AFTERNOON.
ADJUSTED POPS/WX TIMING ACCORDING TO SREF/NAM DETAILS. MINOR CHANGES
NEEDED FOR TEMPS THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS APPEAR TO BE IN BETTER AGREEMENT WITH THE OVERALL PATTERN.
WEATHER CONTINUES TO REMAIN UNSETTLED FOR THE FIRST PART OF THE LONG
TERM AS THE UPPER LOW FINALLY MOVES OFF TO THE EAST ACROSS
OHIO...BEFORE FINALLY MOVING ACROSS NEW ENGLAND BY MID WEEK. LIGHT
SNOW SHOWERS WILL CONTINUE TO OCCUR THROUGH THE FIRST PART OF THE
WEEK UNDER THE INFLUENCE OF THE UPPER LEVEL LOW...ESPECIALLY IN
FAVORED UPSLOPE AREAS IN THE NORTHERN AND CENTRAL MOUNTAINS IN THE
NW FLOW BEHIND THE LOW AS IT CONTINUES TO MOVE EASTWARD. A BRIEF
BREAK IS EXPECTED IN THE PRECIPITATION MID WEEK AS HIGH PRECIPITATION MID WEEK AS HIGH PPRECIPITATION MID WEEK AS HIGH PRESSURE
ATTEMPTS TO BRIEFLY BUILD IN...BUT ANOTHER SYSTEM IS EXPECTED TO
ARRIVE LATE IN THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
GREENBRIER AND TYGART VALLEYS IN THE MOUNTAINS WILL HAVE LIFR FOG
THROUGH 14Z OR SO. ALSO...SOME VALLEYS WITHIN THE SOUTHERN LOWLANDS
MAY GET IFR FOG FOR A TIME...BUT HIGH CLOUDS AND DRIER AIR MASS
COMPARED TO RECENT NIGHTS WILL PREVENT IFR FOG FORMATION FOR MOST
LOCATIONS. GOING INTO TONIGHT...LLWS WILL BE A THREAT AS PRESSURE
GRADIENT GREATLY INCREASES...AND NEAR-SURFACE INVERSION KEEPS
HIGHEST WINDS NOT VERY FAR OFF OF THE GROUND.
AFTER 06Z FRIDAY...
SYSTEM IMPACTS AREA FRIDAY...WITH RAIN AND POSSIBLE IFR.
FREEZING RAIN ALSO A THREAT IN THE WV MOUNTAIN VALLEYS...AND LOW
LEVEL WIND SHEAR NOT OUT OF THE QUESTION AREAWIDE FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON
FOR WVZ046-047.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR
WVZ033>036.
OH...NONE.
KY...NONE.
VA...HIGH WIND WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR
VAZ003-004.
&&
$$
SYNOPSIS...ARJ/SL/JS
NEAR TERM...26/JS
SHORT TERM...ARJ
LONG TERM...SL
AVIATION...MDP
